You are getting this response because possibly, the total number of open invoices exceeded the Row Limit or maximum number of transactions a sublist can accommodate
Below are the steps that you may take to avoid the problem. You have to filter the invoices by date to narrow down the result.
1. Please navigate to Transactions > Customers > Issue Credit Memos
2. Go to Items Tab > Apply Subtab
3. Click Customize button
4. Check the Include checkbox for 'Date' and 'Number/ID' under Additional Filters Tab
5. Click Save.
6. Go back to Items Tab > Apply Subtab
7. Set the Date = This Month or any preferred date range8. Alternatively, you can type the Invoice number on the Number/ID filter.